In a conventional data center, service nodes generally exist in a physical form, a quantity of the service nodes is limited, and locations of the service nodes are fixed; therefore, the service nodes are manually configured. However, network virtualization brings the following new requirements:
1. A virtualized multi-tenant requirement: Separation of tenants' services requires that each tenant network should have different types and quantities of service nodes.
2. Cloud interconnection of data centers: Multiple data centers are interconnected to form a virtual cloud data center, causing that a quantity of service nodes increases sharply, and a virtual service node can be deployed at any location.
3. After an original service node supported by special-purpose hardware is virtualized, the hardware with high performance is replaced by a virtual machine Due to the performance degradation, efficiency of the service node is reduced, a burden becomes heavier as tenants increase, and a fault or overload easily occurs.
In conclusion, after network functions are virtualized, a large quantity of service nodes need to be managed, and it becomes more complex to support reliability, high availability, and scalability of the service nodes; therefore, conventional manual configuration obviously cannot meet the requirements.